The book starts in June 1931. Clairvaux is where Edgar went to prison to. Clairvaux Abbey was a Cistercian monastery in Ville-sous-la-Ferté, 15 kilometres from Bar-sur-Aube. The abbey was founded in 1115 by Bernard of Clairvaux. As a primary abbey, it was one of the most significant monasteries in the order. Dissolved during the French Revolution, it was used from 1808 to 2023 as Clairvaux Prison, a high-security correctional facility.